ODP: Hydra Design Goals: How important is RDF?

>>The Hydra Core Vocabulary is a vocabulary to describe hypermedia controls.
>>So Hydra Core Vocabulary constructs will be inside of API responses.
>>That's not the case with service description stuff like WSDL, Swagger, etc.

Well, I’m somehow dissappointed and I hope Hydra to be more than this.
While hypermedia is something what we seek I’m not that keen to throw everyhing into API responses altogether.
I like to have separated raw data and hypermedia controls. I feel that my point of view is not that abandoned.
The spec points to API documentation in very first paragraphs, thus I hope we’ll not close ourselves only to having embedded hypermedia controls.
I think this will greatly limit the use cases for Hydra itself and will become it’s first nail to the coffin.

Best,
Karol Szczepański


Od: Ruben Verborgh
Wysłano: czwartek, 1 października 2015 11:50
Do: Asbjørn Ulsberg
DW: Hydra
Temat: Re: Hydra Design Goals: How important is RDF?


> As with JSON-LD, I feel the RDF part of Hydra is both
> under-communicated and more of a nice-to-have than the core value of
> the technologies. I think this is a good thing. While RDF and the
> Semantic Web is awesome in its prospects, I highly doubt most people
> getting their hands dirty with JSON-LD or Hydra will have a Semantic
> Web perspective or problems related to RDF to solve.

Yes, and it that sense Hydra is a great bridge.

However, let's be very clear here:
– JSON-LD without RDF is just JSON
– just JSON is not self-descriptive
– without self-descriptiveness, Hydra becomes a spec like all others

For the last point, we build intelligent clients
that strongly rely on the self-descriptiveness of interfaces.

> Related and relevant: "JSON-LD and Why I Hate the Semantic Web"
> http://manu.sporny.org/2014/json-ld-origins-2/

I also recommend people to read this,
but for different reasons: it explains well how to write a spec.

> I expect JSON-LD to be used as a way to express URIs and hypermedia in
> JSON and I expect Hydra to be used as "The WSDL of HTTP / REST".
> Please arrest me if I'm wrong in these assumptions.

I don't agree.
The Hydra Core Vocabulary is a vocabulary to describe hypermedia controls.
So Hydra Core Vocabulary constructs will be inside of API responses.
That's not the case with service description stuff like WSDL, Swagger, etc.

Additionally, it allows to describe the structure of an API.

> Because of this, I think it's important to state this nice-to-have
> status of RDF as a design goal, since from what I've gathered so far
> from the discussions on this list, this isn't necessarily something
> everyone is in agreement with.

RDF is a means, not a goal.
RDF enables self-descriptiveness, which is a goal.

Best,

Ruben